A light emitting diode (LED) is driven by direct current (DC) power. Hence, in order to substitutively employ an LED illuminating apparatus as a light source in a lamp driven by alternating current (AC) power, a driving device is required. In addition, a ballast stabilizer for a fluorescent lamp outputs an appropriate amount of power for driving a fluorescent lamp. Hence, if an LED illuminating apparatus exhibiting electrical characteristics different from those of a fluorescent lamp is used, the LED illuminating apparatus may not operate normally or a device component may be damaged. As a solution thereto, a ballast stabilizer installed in a fluorescent lamp is removed and a power supplier for an LED illuminating apparatus is installed instead. Thus, a light source driving device, allowing for compatibility between a ballast stabilizer for a fluorescent lamp and an LED illuminating apparatus is required.